1,302 research outputs found

    Are we really that different from each other? The difficulties of focusing on similarities in cross-cultural research.

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    In this article we argue that there are 2 dominant underlying themes in discussions of strategies for dealing with diversity—similarity and difference. When we are dealing with social groups, a number of basic psychological processes, as well as popular media and research-based narratives, make it easier to highlight difference rather than similarity. This difference-based approach in research is inherently divisive, but the training that we receive as researchers in the field of psychology has taken us down this path. As a first step, we propose that researchers working in the area of cultural diversity should start making explicit attempts to highlight similarities between groups, even if such similarities are only based on the absence of observed statistical differences. Moreover, if we are going to be serious about demonstrating similarity between groups and certain types of universals in behavior, we should start embracing new approaches to data analyses and consider using statistical procedures that test for equivalence. We illustrate these new techniques using our own data. Finally, we argue that shifting our primary focus from difference to similarity is a worthwhile direction to pursue for successfully managing diversity in multicultural societies.Social Sciences and Humanities Research Council (SSHRC

    Regulation of Motor Function and Behavior by Atypical Chemokine Receptor 1

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10519-014-9665-7Atypical Chemokine Receptor 1 (ACKR1), previously known as the Duffy Antigen Receptor for Chemokines, stands out among chemokine receptors for its high selective expression on Purkinje cells of the cerebellum, consistent with the ability of ACKR1 ligands to activate Purkinje cells in vitro. Nevertheless, evidence for ACKR1 regulation of brain function in vivo has been lacking. Here we demonstrate that Ackr1−/− mice have markedly impaired balance and ataxia when placed on a rotating rod and increased tremor when injected with harmaline, a drug that induces whole-body tremor by activating Purkinje cells. Ackr1−/− mice also exhibited impaired exploratory behavior, increased anxiety-like behavior and frequent episodes of marked hypoactivity under low-stress conditions. The behavioral phenotype of Ackr1−/− mice was the opposite of the phenotype occurring in mice with cerebellar degeneration and the defects persisted when Ackr1 was deficient only on non-hematopoietic cells. We conclude that normal motor function and behavior depend in part on negative regulation of Purkinje cell activity by Ackr1

    Deep Markov Random Field for Image Modeling

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    Markov Random Fields (MRFs), a formulation widely used in generative image modeling, have long been plagued by the lack of expressive power. This issue is primarily due to the fact that conventional MRFs formulations tend to use simplistic factors to capture local patterns. In this paper, we move beyond such limitations, and propose a novel MRF model that uses fully-connected neurons to express the complex interactions among pixels. Through theoretical analysis, we reveal an inherent connection between this model and recurrent neural networks, and thereon derive an approximated feed-forward network that couples multiple RNNs along opposite directions. This formulation combines the expressive power of deep neural networks and the cyclic dependency structure of MRF in a unified model, bringing the modeling capability to a new level. The feed-forward approximation also allows it to be efficiently learned from data. Experimental results on a variety of low-level vision tasks show notable improvement over state-of-the-arts.Comment: Accepted at ECCV 201

    Adenosine A 1 -Receptor Modulation of Glutamate- Induced Calcium Influx in Rat Retinal Ganglion Cells

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    PURPOSE. Although adenosine receptors (A 1 -Rs and A 2 -Rs) have been identified in the mammalian retina, the role of adenosine in this tissue is not fully understood. The purpose of this work was to investigate the action of adenosine on glutamate-induced calcium influx in rat retinal ganglion cells (RGCs) and to determine whether adenosine modulates RGC voltage-gated calcium channels. METHODS. Purified RGC cultures were generated from neonatal rats with a two-step panning procedure. Isolated RGCs were loaded with the ratiometric calcium-indicator dye fura-2, and the effect of adenosine (and related agonists and antagonists) on intracellular calcium levels ([Ca 2ϩ ] i ) during exposure to glutamate (10 M with 10 M glycine) was assessed. The effect of adenosine on calcium channel currents was also studied in isolated RGCs with whole-cell patch-clamp techniques. In addition, the effect of adenosine on [Ca 2ϩ ] i was investigated in fura dextran-loaded RGCs in an intact adult rat retina preparation. RESULTS. In isolated RGCs, adenosine (10 and 100 M) significantly reduced the glutamate-induced increase in [Ca 2ϩ ] i (ϳ30%). The effect of adenosine was blocked by the A 1 -R antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), but not by the A 2 -R antagonist 3,7-dimethyl-1-propargylxanthine (DMPX). Adenosine (10 M) inhibited calcium channel currents by 43%, and again this effect was blocked by DPCPX, but not DMPX. Adenosine (100 M) also significantly reduced the elevation of [Ca 2ϩ ] i in RGCs in the intact retina during exposure to N-methyl-D-aspartate (NMDA; 100 M). CONCLUSIONS. Adenosine can inhibit glutamate-induced calcium influx and voltage-gated calcium currents in rat RGCs through A 1 -R activation. This work supports a role for adenosine as a neuromodulator of mammalian RGCs. (Invest Ophthalmol Vis Sci

    Birational cobordism invariance of uniruled symplectic manifolds

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    A symplectic manifold (M,ω)(M,\omega) is called {\em (symplectically) uniruled} if there is a nonzero genus zero GW invariant involving a point constraint. We prove that symplectic uniruledness is invariant under symplectic blow-up and blow-down. This theorem follows from a general Relative/Absolute correspondence for a symplectic manifold together with a symplectic submanifold. A direct consequence is that symplectic uniruledness is a symplectic birational invariant. Here we use Guillemin and Sternberg's notion of cobordism as the symplectic analogue of the birational equivalence.Comment: To appear in Invent. Mat

    Towards a better understanding of the dynamic role of the distance language learner: learner perceptions of personality, motivation, roles, and approaches

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    This study investigated the experience of learners enrolled on an Open University (UK) French course, and included personality factors, motivation, and tutor and student roles. The data gathered via multiple elicitation methods gave useful insights into issues of special relevance to distance language education, in particular the lack of fit between an inherently social discipline such as language learning and the distance context, whose main characterizing feature is remoteness from others. Motivation was seen to play a crucial role in success, along with tutor feedback, and personal responsibility for learning. Increased confidence and self?regulation were beneficial outcomes of the process of learning at a distance, and numerous suggestions for learning approaches based on personal experience were offered for language learners new to distance learning. The study concluded that the task for distance practitioners is to build on the insights shown by learners themselves, in order to target support where it is most needed

    Autism as a disorder of neural information processing: directions for research and targets for therapy

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    The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself

    Hopf algebras and Markov chains: Two examples and a theory

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    The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

    Motor-Coordination-Dependent Learning, More than Others, Is Impaired in Transgenic Mice Expressing Pseudorabies Virus Immediate-Early Protein IE180

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    The cerebellum in transgenic mice expressing pseudorabies virus immediate-early protein IE180 (TgIE96) was substantially diminished in size, and its histoarchitecture was severely disorganized, resulting in severe ataxia. TgIE96 mice can therefore be used as an experimental model to study the involvement of cerebellar circuits in different learning tasks. The performance of three-month-old TgIE96 mice was studied in various behavioral tests, including associative learning (classical eyeblink conditioning), object recognition, spatial orientation (water maze), startle response and prepulse inhibition, and passive avoidance, and compared with that of wild-type mice. Wild-type and TgIE96 mice presented similar reflexively evoked eyeblinks, and acquired classical conditioned eyelid responses with similar learning curves for both trace and delay conditioning paradigms. The two groups of mice also had similar performances during the object recognition test. However, they showed significant differences for the other three tests included in this study. Although both groups of animals were capable of swimming, TgIE96 mice failed to learn the water maze task during the allowed time. The startle response to a severe tone was similar in both control and TgIE96 mice, but the latter were unable to produce a significant prepulse inhibition. TgIE96 mice also presented evident deficits for the proper accomplishment of a passive avoidance test. These results suggest that the cerebellum is not indispensable for the performance of classical eyeblink conditioning and for object recognition tasks, but seems to be necessary for the proper performance of water maze, prepulse inhibition, and passive avoidance tests
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